Little Seung-jae stays up all night and writes letters to So-hee, pretending to be her father in Mars. Leaving Seung-jae's innocent heart behind, So-hee leaves for a big city. Both grown up to be adults, Seung-jae is a postman who writes letters to So-hee's grandma - the letters that never came from So-hee. So-hee's heart hardens after hardships in life and she comes back to her hometown and Seung-jae's heart swells up again at seeing her again...

Two friends - Min-gyu, a wild-animal vet, and Eun-hae, a fashion photographer - commiserate with each other when each realizes that the person they love is no longer in love with them. In anger, Eun-hae smashes up her boyfriend's car; in frustration, Min-gyu breaks glasses and carves up a spider. Min-gyu and Eun-hae each urge the other to be calm, to move on, to forget about it. Good advice, if only they could take it. "Why do humans need love?," these friends ask each other. Can jealousy, anger, and desire for revenge lead two jilted lovers to embrace what they have? Will someone dream of a giraffe?